: RE:We water treatment guys use flow controls when needed, not undersized tubing and for a solution feeder, there is no need to control the flow.

: Many times rather then go for a mechanical device like "flow control devices" we can do it math mathematically.

: For example if a filter has a rating of no more then 20 GPM to remove sediment all one would have to do is find the in coming pressure.

: Lets assume that the available pressure is 65 PSI and we are running 3/4 lines, the volume flowing would hover around 39.37 GPM thus rendering the filter useless.

: Now if the installer used 1/2" prior to going into this filter the VOLUME flowing through this piping would be 17.5 GPM still well with in the filters capacity to remove sediment without causing undo turbulence.

: This is especially true on acid crock systems, like a floor drain in a battery room or in a laboratory where this acidic waste has to be controlled prior to entering the neutralizing tank.

: Too fast and the marble chips will not have time to do their job and not every installation has room to have a holding tank.

: Thus we have to depend on piping sized to reduce volume rather then figuring baffles or mechanical devices that are prone to failure

: : Look at the common grease trap for example. Flow rates are critical, even in boilers with hot water tankless coil applications one uses piping of various sizes to get the desired effect.

: Older heating steam and hydronics depended on piping being increased or decreased depending on what the condition needed.